1. Field of the Invention
This invention has to do with propelled mechanical harvesters designed for use in harvesting crops that grow on sturdy vines or on trees. Vine crops include such crops as berry bushes and grape vines. Tree crops harvest able by this invention include fruits and nuts or other similar crops.
More specifically, the invention presented here is a shaker head using a force balanced drive in a unique layout and arrangement that will provide significant force needed to shake product from the plant but will do so without imparting significant vibration to the mobile frame of the harvester itself. The shaking motion of this invention is a side-to-side motion that is naturally directed to a single plane of operation. As the motion of the shaker is directed to this single plane the undesirable lost motion of a multi plane or pivoting shaker head is eliminated.
2. Description of the Prior Art
The mechanical harvesting of vine products, such as grapes, is a tumultuous industry that has seen numerous developments in recent years. No mechanical harvester manufacturer has come up with the "be all and end all" machine that dominates the market. Advancements occur sporadically and with the cyclical harvest schedule the advances in the art are taken in a stepped progression rather then a smooth evolution.
General information regarding harvesters of the type described herein, it being noted that these harvesters rely on a pivoting head and shaker motion, can be gleaned from a perusal of U.S. Pat. Nos. 4,286,426 for a "Vibratory Fruit Harvester"; 4,336,682 for a "Continuous Harvester For Plants Grown in Rows"; 4,432,190 for a "Continuous Harvester For Plants Grown in Rows"; and 5,495,708 for a "Canopy Harvester With Force Balanced Drive." The references cited in these patents will also be of interest in gaining knowledge of the vibratory harvester industry.
U.S. Pat. No. 4,793,128 to Creed for a Horizontal Force Balanced Shaker and Method presents an embodiment of shaker that includes a force balance shaker driving a parallelogram-type translation function. This device does not have the horizontal bars that are used in the instant invention and assure the horizontal movement of the shaker bars. The Creed shaker has a complex drive system used to get equal force at each end of the shaker. It also has an upward vector in the travel of the bars due to the parallelogram linkage.
A U.S. Patent entitled "Counterweight Method and System for a Beater Rod of a Harvester," Number 4,982,558, shows the use of counter rotating weights in a vertical harvesting system.
Up until about fifteen years ago mechanical harvesting of grapes was rare and some of the most important and astute growers and farmers were hesitant to harvest using mechanical means due to perceived damage to crops. It has taken many years and equipment iterations to convince the sophisticated growers in the industry that mechanical harvesting was a safe means of bringing in the crop. Some growers believed vine damage from use of what are know as foliage shakers were too hard on the crop. Damage to canes, leaves and new bud growth, not to mention the volume of leaves and "trash" picked with the grapes, was not tolerable and the industry turned to stump shakers that allowed mechanical harvesting without damage to the foliage mass.